WINCHESTER 115gr fmj/hb -VS- fmj/fb

JAMESACERRA · September 7, 2009, 04:19 PM

Hi Y'all
Whats the differences in Winchester 115 grn FMJ/Hollow base -vs- FMJ/Flat base in reloading?
Thanks for any assistance.
Yours in service
James Acerra

Sevens · September 7, 2009, 06:26 PM

Do you have a link which has both so that we could better see EXACTLY what they are offering?

What I mean is, I've seen some actual hollow-based bullets where there is a serious concave base, little a little pit in the base of the bullet-- I've seen these from Berry's. They are plated bullets, not jacketed.

Some makers build a FMJ bullet that they call "TMJ" or "completely metal jacketed" which means even the base of the bullet is copper jacketed. (typically, the run of the mill FMJ bullet will have a plain lead base) The idea with TMJ bullets is to reduce the chance of airborne lead particles for air quality on indoor ranges.

So I'd like to see a link for the source you are looking at that offers both.

IMO, if the base is not a hugely hollowed-out concave bullet, the load probably won't differ much at all, if any. Obviously, a bullet with the base hollowed-out would offer a little more internal space which would theoretically lower the pressure a bit as there is more space inside the loaded round.

The other difference that's possible if the bullets are the same weight but one has a hollowed-out base is that the length of the bullet must make up for the area which has been hollowed out. Thus... a concave based bullet the same weight would most likely have to be physically longer.

I would venture a guess that unless you are running the extreme ragged edge of a max or hot load, this is much ado about nothing.

Sorry about the rambling and over-long nature of my reply!

rg1 · September 7, 2009, 08:05 PM

Only info I have is from Midways LoadMap Series 9mm from 1998. They tested both the FMJ and the FMJ-HB 115 grain bullets. They used Win SP primers and RP cases in their tests using a universal receiver 4" barrel. Overall lengths for the 115 grain Win bullets tested were long with the FMJ tested at 1.165" and the FMJ-HB at 1.169". Only thing I can think of would be that the hollow base like in a lead bullet may expand and seal the gas a little better?
I picked same charges of 5 different powders (not start charges and not maximum charges) and pressures and velocities doesn't show any consistent differences.
fmj----Bullseye 4.0--29400psi--1072fps
HB----Bullseye 4.0--28000----1056
fmj---Unique 5.0--25300psi--1060fps
HB---Unique 5.0--27700-----1090
fmj---HS6-----6.4--30500-----1131
HB----HS6----6.4--29700-----1123
fmj---Win231--4.2--27800----1023
HB---Win231--4.2--27500-----1020
fmj--AA#5----6.3--28100-------1098
HB--AA#5----6.3--29300--------1117
So these numbers doesn't show much difference with some loads with the FMJ showing more pressure and some with the Hollow Base showing more pressure. Just for comparison. Use your load data for starting charges.

rc · September 7, 2009, 10:58 PM

Hollow base gives you more room for powder over flat base. Basic construction is the same. Don't know much about accuracy difference. More powder capacity is good if you want to max out your velocity.

JAMESACERRA · September 8, 2009, 02:40 AM

Hi Y'all
Thanks for all the tips.
I'll try to find a pic of said bases.
Yours in service
James Acerra

zeke · September 8, 2009, 08:40 PM

The main difference is the hb bullet has a longer bearing length, and easier to load to a longer COL without bullet setback.

September 7, 2009, 04:19 PM	#1
JAMESACERRA Junior Member Join Date: September 7, 2009 Location: Arkansas Posts: 2	WINCHESTER 115gr fmj/hb -VS- fmj/fb Hi Y'all Whats the differences in Winchester 115 grn FMJ/Hollow base -vs- FMJ/Flat base in reloading? Thanks for any assistance. Yours in service James Acerra __________________ GUN CONTROL is HITTING you TARGET

September 7, 2009, 06:26 PM	#2
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,757	Do you have a link which has both so that we could better see EXACTLY what they are offering? What I mean is, I've seen some actual hollow-based bullets where there is a serious concave base, little a little pit in the base of the bullet-- I've seen these from Berry's. They are plated bullets, not jacketed. Some makers build a FMJ bullet that they call "TMJ" or "completely metal jacketed" which means even the base of the bullet is copper jacketed. (typically, the run of the mill FMJ bullet will have a plain lead base) The idea with TMJ bullets is to reduce the chance of airborne lead particles for air quality on indoor ranges. So I'd like to see a link for the source you are looking at that offers both. IMO, if the base is not a hugely hollowed-out concave bullet, the load probably won't differ much at all, if any. Obviously, a bullet with the base hollowed-out would offer a little more internal space which would theoretically lower the pressure a bit as there is more space inside the loaded round. The other difference that's possible if the bullets are the same weight but one has a hollowed-out base is that the length of the bullet must make up for the area which has been hollowed out. Thus... a concave based bullet the same weight would most likely have to be physically longer. I would venture a guess that unless you are running the extreme ragged edge of a max or hot load, this is much ado about nothing. Sorry about the rambling and over-long nature of my reply! __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.

September 7, 2009, 08:05 PM	#3
rg1 Senior Member Join Date: November 6, 2001 Posts: 1,125	Only info I have is from Midways LoadMap Series 9mm from 1998. They tested both the FMJ and the FMJ-HB 115 grain bullets. They used Win SP primers and RP cases in their tests using a universal receiver 4" barrel. Overall lengths for the 115 grain Win bullets tested were long with the FMJ tested at 1.165" and the FMJ-HB at 1.169". Only thing I can think of would be that the hollow base like in a lead bullet may expand and seal the gas a little better? I picked same charges of 5 different powders (not start charges and not maximum charges) and pressures and velocities doesn't show any consistent differences. fmj----Bullseye 4.0--29400psi--1072fps HB----Bullseye 4.0--28000----1056 fmj---Unique 5.0--25300psi--1060fps HB---Unique 5.0--27700-----1090 fmj---HS6-----6.4--30500-----1131 HB----HS6----6.4--29700-----1123 fmj---Win231--4.2--27800----1023 HB---Win231--4.2--27500-----1020 fmj--AA#5----6.3--28100-------1098 HB--AA#5----6.3--29300--------1117 So these numbers doesn't show much difference with some loads with the FMJ showing more pressure and some with the Hollow Base showing more pressure. Just for comparison. Use your load data for starting charges.

September 7, 2009, 10:58 PM	#4
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,776	Hollow base gives you more room for powder over flat base. Basic construction is the same. Don't know much about accuracy difference. More powder capacity is good if you want to max out your velocity.

September 8, 2009, 02:40 AM	#5
JAMESACERRA Junior Member Join Date: September 7, 2009 Location: Arkansas Posts: 2	FMJ/FB -vs-- FMJ/HB Hi Y'all Thanks for all the tips. I'll try to find a pic of said bases. Yours in service James Acerra __________________ GUN CONTROL is HITTING you TARGET

September 8, 2009, 08:40 PM	#6
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	The main difference is the hb bullet has a longer bearing length, and easier to load to a longer COL without bullet setback.